Will cmmflush cause WMB or IIB to release memory that may build up over the week in the execution groups?
Chris Will -----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Marcy Cortes Sent: Thursday, July 09, 2015 12:00 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: How to find a memory leak? Easier, but the pages aren't dropped from the zVM side immediately so if you are memory constrained there, cmmflush is your friend. -----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Michael MacIsaac Sent: Thursday, July 09, 2015 8:51 AM To: LINUX-390@VM.MARIST.EDU Subject: Re: [LINUX-390] How to find a memory leak? Tomas, > I forgot to answer this question: you can drop buffers and cache by running > echo 3 > /proc/sys/vm/drop_caches Nice, even easier. Thanks! The next question is - can this ever be done by a non-root user? I tried adding /bin/echo to /etc/sudoers, but still get an error: mike@lab153:~ $ sudo /bin/echo 3 > /proc/sys/vm/drop_caches -bash: /proc/sys/vm/drop_caches: Permission denied -Mike On Thu, Jul 9, 2015 at 11:36 AM, Pavelka, Tomas <tomas.pave...@ca.com> wrote: > > Thanks. I copied and pasted cmmflush and it seems to work nicely > > If I understand it right then you have to look at how cmmflush affects > the output of /proc/buddyinfo. If you see non-zero in the last order > of slab (i.e. the one with 1MB size) then you are good to run vmcp > --buffer=1M. > Otherwise you may still run into problems even if free -m shows a lot > of free memory. > > But I have not tried cmmflush, maybe it will help. > > The way that I was able to reproduce the memory fragmentation problem > was by copying large amount of data over SCP to that Linux machine. > Try that and see if you can reproduce the vmcp --buffer=1M failure. > > Tomas > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/ The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association.
